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mailwrapper.c revision 1.3 
      1 /*	$NetBSD: mailwrapper.c,v 1.3 1999/05/29 18:18:15 christos Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1998
      5  * 	Perry E. Metzger.  All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgment:
     17  *	This product includes software developed for the NetBSD Project
     18  *	by Perry E. Metzger.
     19  * 4. The name of the author may not be used to endorse or promote products
     20  *    derived from this software without specific prior written permission.
     21  *
     22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     23  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     24  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     25  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     26  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     27  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     28  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     29  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     30  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     31  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     32  */
     33 
     34 #include <err.h>
     35 #include <stdio.h>
     36 #include <string.h>
     37 #include <stdlib.h>
     38 #include <unistd.h>
     39 #include <util.h>
     40 
     41 #define _PATH_MAILERCONF	"/etc/mailer.conf"
     42 
     43 struct arglist {
     44 	size_t argc, maxc;
     45 	char **argv;
     46 };
     47 
     48 int main __P((int, char *[], char *[]));
     49 
     50 static void initarg __P((struct arglist *));
     51 static void addarg __P((struct arglist *, const char *, int));
     52 static void freearg __P((struct arglist *, int));
     53 
     54 extern const char *__progname;	/* from crt0.o */
     55 
     56 static void
     57 initarg(al)
     58 	struct arglist *al;
     59 {
     60 	al->argc = 0;
     61 	al->maxc = 10;
     62 	if ((al->argv = malloc(al->maxc * sizeof(char *))) == NULL)
     63 		err(1, "mailwrapper");
     64 }
     65 
     66 static void
     67 addarg(al, arg, copy)
     68 	struct arglist *al;
     69 	const char *arg;
     70 	int copy;
     71 {
     72 	if (al->argc == al->maxc) {
     73 	    al->maxc <<= 1;
     74 	    if ((al->argv = realloc(al->argv,
     75 		al->maxc * sizeof(char *))) == NULL)
     76 		    err(1, "mailwrapper");
     77 	}
     78 	if (copy) {
     79 		if ((al->argv[al->argc++] = strdup(arg)) == NULL)
     80 			err(1, "mailwrapper:");
     81 	} else
     82 		al->argv[al->argc++] = (char *)arg;
     83 }
     84 
     85 static void
     86 freearg(al, copy)
     87 	struct arglist *al;
     88 	int copy;
     89 {
     90 	size_t i;
     91 	if (copy)
     92 		for (i = 0; i < al->argc; i++)
     93 			free(al->argv[i]);
     94 	free(al->argv);
     95 }
     96 
     97 int
     98 main(argc, argv, envp)
     99 	int argc;
    100 	char *argv[];
    101 	char *envp[];
    102 {
    103 	FILE *config;
    104 	char *line, *cp, *from, *to, *ap;
    105 	size_t len, lineno = 0;
    106 	struct arglist al;
    107 
    108 	initarg(&al);
    109 	for (len = 0; len < argc; len++)
    110 		addarg(&al, argv[len], 0);
    111 
    112 	if ((config = fopen(_PATH_MAILERCONF, "r")) == NULL)
    113 		err(1, "mailwrapper: can't open %s", _PATH_MAILERCONF);
    114 
    115 	for (;;) {
    116 		if ((line = fparseln(config, &len, &lineno, NULL, 0)) == NULL) {
    117 			if (feof(config))
    118 				errx(1, "mailwrapper: no mapping in %s",
    119 				    _PATH_MAILERCONF);
    120 			err(1, "mailwrapper");
    121 		}
    122 
    123 #define	WS	" \t\n"
    124 		cp = line;
    125 
    126 		cp += strspn(cp, WS);
    127 		if (cp[0] == '\0') {
    128 			/* empty line */
    129 			free(line);
    130 			continue;
    131 		}
    132 
    133 		if ((from = strsep(&cp, WS)) == NULL)
    134 			goto parse_error;
    135 
    136 		cp += strspn(cp, WS);
    137 
    138 		if ((to = strsep(&cp, WS)) == NULL)
    139 			goto parse_error;
    140 
    141 		if (strcmp(from, __progname) == 0) {
    142 			for (ap = strsep(&cp, WS); ap != NULL;
    143 			    ap = strsep(&cp, WS))
    144 			    if (*ap)
    145 				    addarg(&al, ap, 0);
    146 			break;
    147 		}
    148 
    149 		free(line);
    150 	}
    151 
    152 	(void)fclose(config);
    153 
    154 	execve(to, al.argv, envp);
    155 	freearg(&al, 0);
    156 	free(line);
    157 	err(1, "mailwrapper: execing %s", to);
    158 	/*NOTREACHED*/
    159 parse_error:
    160 	freearg(&al, 0);
    161 	free(line);
    162 	errx(1, "mailwrapper: parse error in %s at line %lu",
    163 	    _PATH_MAILERCONF, (u_long)lineno);
    164 	/*NOTREACHED*/
    165 }
    166